Figure 1-5. Fisher and Bunsen burners.
(1) Adjusting the flame. At the base of the burner are vents through which
the air enters. This air is mixed with incoming gas. The amount of air is adjusted by
screwing the tube up or down on a threaded base. The amount of gas is regulated by
turning the disk (gas valve) at the base. Together, these devices can be used to control
the size and intensity of the flame.
(2) Temperatures available. It is important for you to know the temperature
at various points within the flame. This knowledge will enable you to heat substances at
the proper temperature and to position the substance to be heated to attain the hottest
temperature. Figure 1-6 compares the flame temperatures of both burners at different
levels within each flame.
but its temperature cannot be closely controlled. Never place your glass containers
directly on an electrical heating device because they may break.